Question

why amoeba change its shape?

Answer 1

The amoeba can change its shape to move. amoeba  to move in a certain direction it use temporary projections called psuedopods. This movement involves a solid-gel state change in cytoplasm, and psuedopods are formed by the flow the cytoplasm in the psuedopod changes temporarily into a gel, allowing the amoeba to draw itself upward in the direction of motion.

Answer 2

Amoeba is a single-celled animal and its Greek word means "change." The amoeba can change its shape whenever it wants to. Whenever the amoeba wants to move in a certain direction, little legs push out from that side of its body and draw the rest of the amoeba after it. Whenever it wants to go in another direction it draws in these legs and makes legs on the other side. 

Amoebas move by using temporary projections called psuedopods. This movement involves a solid-gel state change in cytoplasm, and psuedopods are formed by the flow, the cytoplasm in the psuedopod changes temporarily into a gel, allowing the amoeba to draw itself upward in the direction of motion.